Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F4/00—Polymerisation catalysts
  • C08F4/42—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors
  • C08F4/44—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides
  • C08F4/60—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides together with refractory metals, iron group metals, platinum group metals, manganese, rhenium technetium or compounds thereof
  • C08F4/62—Refractory metals or compounds thereof
  • C08F4/64—Titanium, zirconium, hafnium or compounds thereof
  • C08F4/642—Component covered by group C08F4/64 with an organo-aluminium compound
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F10/00—Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F110/00—Homopolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
  • C08F110/02—Ethene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F4/00—Polymerisation catalysts
  • C08F4/42—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors
  • C08F4/44—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides
  • C08F4/60—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides together with refractory metals, iron group metals, platinum group metals, manganese, rhenium technetium or compounds thereof
  • C08F4/62—Refractory metals or compounds thereof
  • C08F4/64—Titanium, zirconium, hafnium or compounds thereof
  • C08F4/659—Component covered by group C08F4/64 containing a transition metal-carbon bond
  • C08F4/65912—Component covered by group C08F4/64 containing a transition metal-carbon bond in combination with an organoaluminium compound
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F4/00—Polymerisation catalysts
  • C08F4/42—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors
  • C08F4/44—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides
  • C08F4/60—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides together with refractory metals, iron group metals, platinum group metals, manganese, rhenium technetium or compounds thereof
  • C08F4/62—Refractory metals or compounds thereof
  • C08F4/64—Titanium, zirconium, hafnium or compounds thereof
  • C08F4/659—Component covered by group C08F4/64 containing a transition metal-carbon bond
  • C08F4/6592—Component covered by group C08F4/64 containing a transition metal-carbon bond containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring
  • C08F4/65922—Component covered by group C08F4/64 containing a transition metal-carbon bond containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring containing at least two cyclopentadienyl rings, fused or not
  • C08F4/65925—Component covered by group C08F4/64 containing a transition metal-carbon bond containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring containing at least two cyclopentadienyl rings, fused or not two cyclopentadienyl rings being mutually non-bridged
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S526/00—Synthetic resins or natural rubbers -- part of the class 520 series
  • Y10S526/943—Polymerization with metallocene catalysts

Definitions

• the present invention relates to novel catalyst compositions and to processes for making polyolefin resins using such novel catalyst compositions, polyolefin resins, and articles made from such polyolefin resins.
• this disclosure relates to processes for making bimodal polyolefin resins using a novel catalyst composition comprising a bimetallic transition metal catalyst precursor and a cocatalyst
• This disclosure also relates to polyolefin resins with improved properties (e.g , improved bubble stability) having bimodal molecular weight distributions and long chain branching, as well as articles made from such polyolefin resins
• U.S. Patent No 4,701 ,432 to Welbor ⁇ , Jr. discloses a catalyst system comprising (i) a metallocene and a non-metallocene transition metal compound (i e a transition metal compound not containing cyclopentadienyl) supported catalyst component and (n) a combination of an organometal c compound of a metal of Groups IA, IIA, IIB and IIIA of the Periodic Table and an alumoxane cocatalyst
• the catalyst composition is disclosed as being useful for olefin polymerization, and particularly for the production of linear low, medium and high density polyethyienes and copolymers of ethylene with alpha-olefms having 3 or more carbon atoms (C 3 -C ⁇ s), cyclic oiefins, and/or diolefins having up to 18 carbon atoms
• U.S. Patent No 5, 157,008 to Sa ⁇ gokoya, et al discloses the production of hydrocarbon solvent solutions of alkylalumoxanes by mixing t ⁇ methylaluminum and a hydrocarbylaluminum compound, which compound contains at least one hydrocarbyl group having 2 or more carbon atoms, in a hydrocarbon solvent and thereafter adding water or a hydrated compound so as to form a solution of alkylaluminoxane in said solvent
• U.S Patent No 5,238,892 to Chang discloses an olefin polymerization catalyst composition comprising a solid product produced by mixing and reacting a metallocene and an aluminum alkyl, for example t ⁇ alkylalummum, in a hydrocarbon solvent to form a reaction product, and thereafter adding an undehydrated support material to the reaction mixture
• U.S Patent No 5,332,706 to Nowlin, et al discloses that the metallocene catalyst must contact the alumoxane (e g , methylalumoxane (MAO)), while the alumoxane is in solution in order for the metallocene to be activated in a fluidized-bed reactor Moreover, the patent discloses that extensive reactor fouling results when MAO solutions are fed directly into the gas phase reactor in large enough quantities to provide this liquid contact. The fouling was found to occur because the MAO solution forms a liquid film on the interior walls of the reactor, and the catalyst is activated when it comes into contact with this liquid film, which in turn leads to the formation of a polymer coating that grows larger in size until the reactor is fouled
• alumoxane e g , methylalumoxane (MAO)
• U S Patent No 5 849,653 to Dall'Occo, et al discloses catalysts for the polymerization of oiefins obtained from cyclopentadienyl compounds of a transition metal, an organometallic aluminum compound, and water
• Japanese Laid-Open Patent Application (Kokai) No 4-266891 discloses a process for producing a methylisobutylalumoxane having high activity and excellent solubility in hydrocarbons It would be desirable to provide a catalyst composition that is capable of producing a bimodal molecular weight distribution (MWD) polyolefin resin with improved properties (e g , bubble stability) having a bimodal molecular weight distribution and long chain branching Further, it would be highly desirable to provide a catalyst composition with high activity from which bimodal polyolefin resins having long chain branching can be produced, wherein the polyolefin resins do not require special post-polymerization tailoring (i e , the polyolefin resins
• a catalyst composition comprising a transition metal catalyst precursor and a cocatalyst, the transition metal catalyst precursor comprising the contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution.
• a catalyst composition comprising a bimetallic transition metal catalyst precursor and a cocatalyst, the bimetallic transition metal catalyst precursor comprising
• a process for polymerizing oiefins comprises contacting one or more oiefins with a catalyst composition comprising a transition metal catalyst precursor and a cocatalyst, the transition metal catalyst precursor comprising the contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution.
• oiefins e g., ethylene and/or higher oiefins
• oiefins e g , ethylene and/or higher oiefins
• the process comprises contacting one or more oiefins with a catalyst composition comprising a bimetallic transition metal catalyst precursor and a cocatalyst, the bimetallic transition metal catalyst precursor comprising (a) the contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution; and (b) a non-metallocene transition metal component
• a polyolefin resin having improved bubble stability is provided, wherein the polyolefin resin has a bimodal molecular weight distribution and long chain branching
• an ethylene (co)polymer is provided, wherein the ethylene (co)polymer is produced in a single reactor and has a bimodal molecular weight distribution, a flow activation energy of at least about 27 kjoule/mole, a density of from about
• Figure 1 shows the bimodal molecular weight distribution of the resm of Example 4 as measured by Gel Permeation Chromatography (GPC)
• Figure 2 shows the bimodal molecular weight distribution of the resin of Example 5 as measured by GPC
• Figure 3 shows the bimodal molecular weight distribution of the resin of Example 6, as measured by GPC
• Figure 4 shows the bimodal molecular weight distribution of the resin of Example 7, as measured by GPC
• the catalyst composition comprises a transition metal catalyst precursor and a cocatalyst, the transition metal catalyst precursor comprising the contact product of an unsubstituted metallocene compound and an aluminum alkyl compound (e g , a t ⁇ alkylaluminum compound) in a hydrocarbon solvent solution
• the transition metal catalyst precursor comprising the contact product of an unsubstituted metallocene compound and an aluminum alkyl compound (e g , a t ⁇ alkylaluminum compound) in a hydrocarbon solvent solution
• Useful metallocene compounds include unsubstituted metallocene compounds that are organometallic coordination compounds of transition metal compounds
• these metallocene compounds may be complexes of a transition metal of the formula L x MQ y Q' 2
• L represents an unsubstituted liga ⁇ d group (e g , cyclopentadienyl)
• M is a transition metal selected from the group consisting of Group 4 metals of the Periodic Chart of the Elements, as published by Chemical and Engineering News, 63(5), 27, 1985, such as titanium, zirconium and hafnium
• each of Q and Q' is a halogen atom, an alkyl group, or a hydrogen atom
• Q and Q' may be the same or different wnerein x is at least 1 and y and z have values such that x+y+z is equal to the valence of M
• a mixture of metallocene compounds is also contemplated
• a typical transition metal atom M is zirconium
• the ligand group L may be an unsubstituted cyclopentadienyl group, where x is at least 1 and typically is 2, and x+y+z equals the valence of M
• the substituents Q and Q' in the above formula of the metallocene complex are halogen atoms, they belong to the group of fluorine chlorine, bromine or iodine, and y + z is 3 or less
• the substituents Q and Q' in the above formula of the metallocene complex are alkyl groups, they are typically linear or branched Ci-Cs alkyl groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, n-hexyl or n-octyl
• Suitable metallocene compounds include, but are not limited to b ⁇ s(cyclopentad ⁇ enyl)metal dihalides, b ⁇ s(cyclopentad ⁇ enyl)metal hyd ⁇ dohalides, b ⁇ s(cyclopentad ⁇ enyl)metal monoalkyl mo ⁇ ohalides, and b ⁇ s(cyclopentad ⁇ enyl)metal dialkyls, wherein the metal is, for example, zirconium, titanium or hafnium atom, the halide atoms are, for example, chlorine and the alkyl groups are Ci-C ⁇ alkyl groups Illustrative but non-limiting examples of metallocene complexes include b ⁇ s(cyclope ⁇ tad ⁇ enyl)z ⁇ rcon ⁇ um dichlo ⁇ de, b ⁇ s(cyclopentad ⁇ e ⁇ yl)t ⁇ tan ⁇ um dichlo ⁇ de, b ⁇ s(cyclopentad ⁇ enyl)ha
• the L x MQ y Q' z compound is contacted with an aluminum alkyl compound, for example a t ⁇ alkyialumi ⁇ um compound
• a suitable hydrocarbon solvent for example a non-aromatic solvent
• the volume of the solvent is sufficient to produce a solution of the contact product
• the solvents which can be used for this purpose include paraffins of 4 to 10 carbon atoms, linear or branched, and are exemplified by n-hexane, isohexane, n-heptane, etc , and their mixtures, as well as cycloalka ⁇ es such as methylcyclopentane, cyclohexane, methylcyclohexane, etc
• the solvent may be an aromatic solvent such as toluene
• suitable aromatic solvents include benzene xyiene or ethylbenzene
• the aluminum alkyl compounds typically t ⁇ alkyialuminum compounds, which are contacted with the L x MQ y Q' z compounds are characterized by the formula AIR 3 , wherein each R may be the same or different and is independently an alkyl group, linear or branched, containing 1 to 12 carbon atoms
• the alkyl groups can be methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, isohexyl, heptyl, isoheptyl, octyl, or isooctyl
• Representative t ⁇ alkylaluminum compounds include, but are not limited to, t ⁇ methylaluminum (TMA), t ⁇ ethylaluminum (TEAL), t ⁇ isobutylaluminum (TIBA), and t ⁇ -n-octylaluminum (TOA)
• the molar ratio of the aluminum alkyl compound to the L x MQ y Q' z complex can range from about 2 to about 50, typically from about 3 to about 40, and most typically from about 4 to about 30
• the concentration of the metallocene compound in the hydrocarbon solvent may range from about 0 1 wt% to about 20 wt% typically from about 0 5 wt% to about 15 wt%
• the transition metal catalyst precursors of the invention may be contacted individually or separately with the aluminum alkyl compound
• the contact product of the transition metal catalyst precursor is formed by contacting the metallocene and the aluminum alkyl compound in a suitable hydrocarbon solvent at a temperature of from about 0°C to about 100°C, typically from about 15°C to about 60°C, for about 1 0 to about 1500 minutes, typically for about 10 to about 180 minutes
• the contact product of the transition metal catalyst precursor may be formed by adding a solution of the t ⁇ alkylaluminum compound to the metallocene compound to form a solution of the contact product
• the process for making the contact product of the transition metal catalyst precursor includes contacting the neat t ⁇ alkylaluminum compound with the metallocene compound to form a solution of the contact product
• a bimetallic transition metal precursor comprises (a) the contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution, as described above, and (b) a non-metallocene transition metal component
• non-metallocene transition metal component (b) may be made by reacting an organomagnesium containing compound, an alcohol, a non-metallocene transition metal compound, and, optionally, a carrier or support
• the support may be inorganic or organic
• the support for the non-metallocene transition metal catalyst component may be any carrier material which contains hydroxyl groups
• a specific support material for the catalyst precursor is a particulate, porous, typically inorganic material, such as an oxide of silicon and/or of aluminum
• the support material is used in the form of a dry powder having an average particle size of from about 1 micron to about 500 microns
• the surface area of the support should be at least about 3 square meters per gram (m 2 /g), and typically from at least 50 m 2 /g up to 400 rrr/g
• the support material should be dry, that is, free of absorbed water Drying of the support material can be effected by heating it at about 100°C to about 1000°C, typically at about 600°C When the support is silica, it is heated to at least about 200°C, typically about 400°C to about 900°C, and more typically about 600°C to about 850°C
• the support material should have at least
• the support is silica which, prior to the use thereof in the catalyst precursor synthesis, has been dehydrated by fluidizing it with nitrogen flow and heating at about 600°C for about 4-16 hours to achieve a surface OH group concentration of about 0 7 millimoles per gram (mmol/g)
• the silica is in the form of spherical particles, which are obtained by a spray-drying process As procured, these silicas are not calcined and thus must be dehydrated as indicated above
• non-metallocene catalyst component (b) may conveniently be carried out in a series of several consecutive steps under inert conditions in the absence of water and of oxygen
• Support material containing OH groups on their surface is slur ⁇ ed in a non-polar non-aromatic solvent
• the slurry of the support material in the solvent is prepared by introducing the support into the solvent, typically while stirring, and heating the mixture to about 25 to about 70°C, typically to about 40 to about 60°C
• Suitable non-polar solvents are materials which are liquid at reaction temperatures and in which all of the reactants used later during the catalyst precursor preparation, i e , organomag ⁇ esium compounds and the non-metallocene transition metal compounds, are at least partially soluble.
• Typical non-polar solvents are alkanes, such as isopentane, hexane, isohexane, ⁇ -heptane, isoheptane, octane, no ⁇ a ⁇ e, and decane, although a variety of other materials including cycloalkanes, such as cyclohexane and methylcyclohexane can also be used.
• alkanes such as isopentane, hexane, isohexane, ⁇ -heptane, isoheptane, octane, no ⁇ a ⁇ e, and decane
• cycloalkanes such as cyclohexane and methylcyclohexane
• aromatic solvents such as benzene, toluene and ethylbenze ⁇ e
• the most typical non-polar solvent is isopentane.
• the non-polar solvent Prior to use, the non-polar solvent should be purified, such as by percolation through silica gel and/or molecular sieves, to remove traces of water, oxygen, polar compounds, and other materials capable of adversely affecting catalyst activity
• the temperature of the slurry is important with respect to its impregnation with a non-metallocene transition metal compound, that is, temperatures of the slurry in excess of 90°C for extended periods may result in deactivation of the transition metal component added subsequently. Accordingly, all catalyst precursor synthesis steps are conducted below 90°C.
• the slurry of the support is contacted with an organomagnesium compound normally provided as a solution
• This solution may contain small quantities of a solubilizing compound such as a trialkylaluminum
• a solubilizing compound such as a trialkylaluminum
• BEM butylethylmagnesium
• t ⁇ ethylaluminum may be complexed with the BEM to solubilize the organomagnesium compound
• MAGALA which is available from Akzo Nobel
• the organomagnesium compound has the empirical formula
• RmMgR'n where R and R' are the same or different C 2 -C ⁇ 2 alkyl groups, typically C 4 -C ⁇ o alkyl groups, more typically C 4 -C 8 alkyl groups, and most typically both R and R' are butyl groups, and m and n are each 0, 1 or 2, providing that m + n is equal to the valence of Mg
• the drying temperature of the support material affects the number of sites on the support available for the organomagnesium compound the higher the drying temperature the lower the number of sites Thus, the exact molar ratio of the organomagnesium compound to the OH groups in the support will vary and must be determined on a
• the amount of the organomagnesium compound added to the slurry may be such that the molar ratio of Mg to the OH groups on the support is about 0 5 1 to about 4 1 , typically about 0 8 1 to about 3 1 , more typically about 0 9 1 to about 2 1 and most typically about 1 1
• the support treated with the organomagnesium compound is contacted with an alcohol (R"OH) containing R"0- groups which are capable of displacing alkyl groups on the magnesium atom
• R"OH an alcohol
• the amount of the alcohol is effective to provide a [R"OH] Mg molar ratio of from about 0 5 to about 2 0, typically from about 0 8 to about 1 5
• the reaction is carried out at a temperature ranging from about 25°C to about 80°C, typically from about 40°C to about 70°C
• the alkyl group R" in the alcohol can contain about 1 to about 12 carbon atoms, typically about 1 to about 8 carbon atoms, in the embodiments below, they are alkyl groups containing about 2 to about 4 carbon atoms, particularly 4 carbon atoms.
• the inclusion of the alcohol step in the catalyst precursor synthesis produces a catalyst composition which, relative to the catalyst precursor prepared without this step, is much more active, requires much less transition metal (e g , titanium), and does not interfere with the performance of the metallocene component in the catalyst
• Suitable transition metal compounds used herein are compounds of metals of Groups 4 and 5, of the Periodic Chart of the Elements as published by Chemical and Engineering News, 63(5), 27, 1985, provided that such compounds are soluble in non- polar solvents
• Non-limiting examples of such compounds are titanium and vanadium halides, e g , titanium tetrachlo ⁇ de, vanadium tetrachlo ⁇ de, vanadium oxyt ⁇ chlo ⁇ de, titanium and vanadium alkoxides, wherein the alkoxide moiety has a branched or unbranched alkyl radical of about 1 to about 20 carbon atoms, typically 1 to about 6 carbon
• the slurry solvent is removed by evaporation or filtering to obtain a free-flowing powder.
• the non-metallocene transition metal component (b) and the contact product (a) are combined to form the bimetallic transition metal catalyst precursor.
• the dried non-metallocene transition metal catalyst component (b) is reslurried in a non-polar hydrocarbon (the same as the solvent used for the preparation of the initial support slurry) and is contacted with a solution containing the contact product (a).
• the contact of (a) and (b) is carried out at temperatures ranging from about 10°C to about 60°C and lasts from about 10 to about 1 ,000 minutes.
• the contact product of the metallocene compound and the aluminum alkyl compound or (ii) the reaction product of the contact product (a) and the non-metallocene transition metal component (b) may be further contacted with a solution of an alumoxane (e.g., MAO or MMAO, which is a modified methylalumoxane from Akzo Nobel).
• alumoxane e.g., MAO or MMAO, which is a modified methylalumoxane from Akzo Nobel.
• the alumoxane is typically provided in an aromatic or aliphatic solvent such as toluene or heptane.
• the use of an alumoxane, in particular MAO has been found to provide an improvement in terms of the homogeneity of the polymer particle morphology.
• the molar ratio of the MAO to the L x MQ y Q' z complex i.e., Al/M molar ratio
• the transition metal catalyst precursor or the bimetallic transition metal catalyst precursor may be used in the form of a free-flowing particulate form. This is obtained by evaporating the solvent(s) used during the catalyst precursor synthesis.
• the catalyst composition also comprises an activating cocatalyst component in addition to the transition metal component
• the cocatalyst may comprise an alumoxane (e g , MMAO obtained from Akzo Nobel), optionally an aluminum alkyl (which may be the same or different as the aluminum alkyl used for the catalyst precursor synthesis), and optionally water
• the resins as described herein are made in one reactor, under suitable reactor conditions
• the bimodal resins are typically made by polymerizing one or more oiefins (e g , ethylene) in the presence of the bimetallic catalyst composition comprising two sources of transition metal each of which produce different molecular weight polymer
• the term "(co)polymer” or “polymer” is inclusive of homopolymers, copolymers made from two different monomers, or interpoiymers of more than two types of monomers (e g , terpolymers) That is, the term copolymer should be construed to include not only polymers made from only two different types of monomers, but also polymers made from three or more different types of monomers (e g , a terpolymer)
• the term "(co)polymer” or “polymer” includes random polymers, block polymers, graft polymers, etc
• the polymerization may be conducted in gas phase (e g , fluidized-bed) or liquid phase (e g , slurry)
• the gaseous monomer feed may, for example, consist wholly of ethylene or may comprise a preponderance of ethylene and a minor amount of one or more comonomers such as a 1 -olefin containing from about 3 to about 10 carbon atoms
• the amount of comonomer(s) may be in the range of, for example, from about 0 to about 30 weight percent, typically from about 0 to about 20 weight percent, based on the total weight of polymer produced in the process
• the resins according to this disclosure include 1 ) a homopolymer of ethylene, or 2) a copolymer of a preponderance ( ⁇ e , greater than 50 wt %) of ethylene with a minor amount of one or more 1 -oiefins containing from about 3 to about 10 carbon atoms, typically 1-olefin(s) containing from about 4 to about 10 carbon atoms, e g , 1 -butene, 1 -pentene, 1 -hexene, 4-methyl-1 -pentene, 1 -octene, 1 -decene, and mixtures thereof, or 3) a mixture of any of the foregoing polymers
• the polymer product can comprise an amount of polymerized comonomer which is in the range, for example, of about 0 to 30 weight percent, based on the total weight of polymer
• hydrogen is typically fed to the reactor such that the molar ratio of hydrogen to ethylene (H 2 /C 2 ratio) is, for example, up to about 0 15, typically from about 0 005 to about 0 03
• the ethylene partial pressure employed in the reactor is usually no higher than about 1 ,724 kPa (250 psia), for example in the range of about 345 kPa (50 psia) to about 1 ,379 kPa (200 psia), typically in the range of about 690 kPa (100 psia) to about 1 ,310 kPa (190 psia)
• an inert gas such as nitrogen may also be present in the reactor in addition to the monomer and hydrogen
• the total pressure in the reactor may be in the range, for example, of about 791 kPa (114 7 psia) to about 4,238 kPa (614 7 psia), typically about 1 ,480 kPa (214 7 psia) to about 2,859 kPa (414 7 psia)
• the temperature of polymerization in the reactor may be in the range, for example, of about 60 to about 130°C, typically about 70 to about 1 10°C
• the residence time of the catalyst in the reactor is about 1 to about 8 hours, typically about 1 5 to about 4 hours in the reactor
• the resins produced by using the catalyst compositions containing the bimetallic transition metal catalyst precursor and the cocatalyst described above are bimodal and also contain long-chain branching (LCB)
• LCB long-chain branching
• bimodal it is meant that there are two polymer components of different molecular weights, that is one has a higher relative molecular weight than the other of the two components
• the presence of LCBs is also beneficial for the bubble stability of the resin during the film blowing process
• the bimodal polyolefin resins described herein do not require special post-polymerization tailoring (i e , the polyolefin resins do not have to be treated with modifiers, such as oxygen or organic peroxides, to modify the mo
• the resins exhibit a characteristic flow activation energy It is believed that the high flow activation energy of the products is indicative of the presence of LCBs, which are known to improve the bubble stability of blown film resins by increasing their melt tension Bubble stability is quantified as the maximum line speed that can be sustained without increasing bubble oscillations on a given blown film line The higher the line speed that the blown film is being fabricated, the thinner the gauge of the film Improved bubble stability is beneficial to a film converter because it allows the production of a thinner film and/or the achievement of higher rates with reduced risk of a downed extrusion line
• the flow activation energy (FAE) of the resins of the present invention is higher than about 27 kjoule/mole
• the FAE measures the temperature dependencies of dynamic viscosity, and these measurements are performed at different temperatures using the RMS 800, over different ranges of temperature, frequency, and strain Rheomet ⁇ cs ® Orchestrator 6 4 3 software can be used for the calculation of FAE
• the dynamic properties used herein are described in ASTM D 4440-84
• the density, the melt index (Ml), high load melt index (HLMI), and melt flow ratio (MFR) of the resins described herein may range as follows
• the properties of the resins are determined by the following test methods- Density ASTM D-1928
• a plaque is made under controlled cooling conditions
• compositions containing the resins described herein can be extruded into pipes, injection or blow molded into articles, or extruded and blown into films Typically, films can be produced which are from about 5 08 to about
• thickness Blow molded articles include bottles, containers fuel tanks and drums
• the products may contain any of various additives conventionally added to polymer compositions such as processing aids, lubricants, antiblock, stabilizers, a ⁇ tioxidants, compatibilizers, pigments, etc
• additives can be employed to stabilize the products against oxidation and/or improve processability, appearance, or properties
• additive packages comprising 400-2000 ppm hindered phenol(s), 200-2000 ppm phosphates, and 250-2000 ppm stearates, for addition to the resin powders, can be used for pelletization
• the polymers can be added directly to a blown film extruder, e g , an Alpine extruder, to produce films having a thickness, for example of about 5 08 to about 127 microns (about 0 2 to about
• the ethylene polymer product of this invention is capable of being formed into thin gauge films, e g , of up to 254 microns (10 mils), of superior mechanical properties, e g , an Elmendorf tear resistance in the machine direction (MD Tear, ASTM D1922) of at least about 236,620 g/m (about 6 g/mil), typically about 314,961 to about 2,362,205 g/m (about 8 to about 60 g/mil), and more typically about 393,701 to about 2,362,205 g/m (about 10 to about 60 g/mil), and a Dart Drop Impact resistance (F50, ASTM D1709) of at least about 50 g, typically about 100 to about 600 g, and more typically about 150 to about 600 g
• MD Tear machine direction
• F50 Dart Drop Impact resistance
• a trusobutylalumi ⁇ um (TIBA)/b ⁇ s-(cyclopentad ⁇ enyl)z ⁇ rcon ⁇ um dichlo ⁇ de (Cp 2 ZrCI 2 ) contact product was prepared by adding a solution of TIBA in hexane (1 0 Molar, 378 82 g solution, 545 mmol of Al) to 1 1 153 g (38 15 mmol) of Cp 2 ZrCI 2 , which produced a yellow solution
• This solution was then added into a two-gallon stainless steel autoclave which contained a slurry of 545 g of the Ti component of Example 1 in ca 2 7 liter of isopentane heated to 50-55°C After the addition the mixture was stirred for approximately 1 hour at 50-55°C
• MAO in toluene 330 77 g solution 1655 mmol Al was added slowly (in a period of approximately 1 hour) to the mixture at 50- 55°C After the addition the mixture was stirred for
• Example 2 The same procedure as described in Example 2 was used, except MMAO in heptane was used instead of MAO in toluene
• 422 g of the Ti component of Example 1 299 42 g solution (431 mmol of Al) of TIBA in hexane, 8 63 g (29 52 mmol) of Cp 2 ZrCI 2 , and 51 1 3 g solution (1266 mmol Al) of MMAO in heptane were employed
• the Ti/Zr catalyst precursors (Examples 2 and 3) were activated with a cocatalyst mixture of MMAO, TMA, and H 2 0
• the resins were produced in a fluidized-bed reactor under the process conditions in the Tables below
• the resins produced from these catalysts were stabilized with the following additive package (2000 ppm Irganox 1010, 2000 ppm Irgafos 168, 2000 ppm zinc stearate) and compounded on a 1 905 cm ( Z ⁇ inch) Brabender extruder under mild conditions (nitrogen purge and 220°C)
• the activation energy of the resultant pellets was measured on the RMS 800 rheometer as discussed earlier
• the activation energy of 38 kjoule/mole indicated the presence of long chain branching
• ethylene and hexene-1 were copolyme ⁇ zed using the activated bimetallic transition metal catalyst precursor of Example 2 under the conditions set out in the Table 1 below
• the resin properties are also indicated in Table 1
• the bimodal molecular weight distribution of the resin as measured by Gel Permeation Chromatography (GPC) is shown in Figure 1 TABLE 1
• the resins had excellent bubble stability as indicated by the maximum line speed being greater than the 91 4 m/min (300 ft/mm) machine limit
• the films had excellent film properties as indicated by dart impacts greater than 400 gms and MD tear values greater than 393,701 g/m (10 g/mil) for a 12.7 microns (0 5 mil) gauge film

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